12S15 CGL

Background Information
A continental-oceanic convergent plate led to the formation of the Mayon Volcano. The Philippine Sea Plate is subduct under the Philippine Mobile Belt forming the Philippine Trench. The melting of the Philippine Sea Plate causing heat and magma to rise through the cracks and crevices to the surface of the earth. After multiple layers of solidified magma have accumulated, Mount Mayon was form.

The volcano is located in the province of Albay, found on the shores of the Gulf of Albay about 10km away. It is part of the Pacific Ring Of Fire.

Mayon Volcanoe has had a long history of destructive eruptions.The first recorded eruption occur in 1616 and since then, about 40 eruptions have claimed more than 1500 lives.

Prediction/Forecasting
On July 10, 2009, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) had raised the status from Alert Level 1 which indicated a low level of unrest to Alert Level 2 which represented moderate unrest. This was because the number of recorded low frequency volcanic earthquakes rose to the same level when a phreatic explosion occurred in an eruption that occurred last August 2008.

On October 28, 2009, a minor ash explosion which lasted for about 1 minute occurred in the summit crater of the volcano. In the prior 24 hours, 13 volcanic earthquakes had been recorded in the prior 24 hours and steam emission was at a moderate level, creeping downslope toward the southwest. PHIVOLCS maintained the Alert Status at Level 2 but later warned that the risk of lahars and possible crater wall collapse due to an approaching tropical cyclone will greatly increase and all specified precautions should be taken.

At 8pm on December 14, 2009, as a result of 83 volcanic quakes in the preceding 24 hours and increased sulfur dioxide emissions, PHIVOLCS raised the Alert Status to Level 3.

Mitigation
Emergency Planning

The Mayon Comprehensive Disaster Prevention Project was implemented by the DPWH and funded by Japan - JBIC Yen Loan Package was proposed to:

1. Mitigate hazards to minimize, if not prevent, the loss of lives and properties due to flows of pyroclastic materials, debris and flood waters

2. Reduce vulnerabilities of the population to such natural elements as volcanic eruption, debris and flood flows and typhoons.

3. Strengthen the institutional and support services.

The project involves the construction of SABO facilities, river improvement, urban flood control/ drainage facilities, forecasting, warning and evacuation system, relocation/resettlement, and institutional and supporting services strengthening. The project area covers the City of Legazpi, and the municipalities of Bacacay, Camalig, Daraga, Guinobatan, Ligao, Malilipot, Malinao, Sto. Domingo, and Tabaco'''. '''

Evacuation Planning

In 2009, Disaster mitigation officials evacuated close to 10,000 families residing within a radius of 6~8km from the crater of the Mayon Volcano after it spewed lava which flowed half a kilometer down-slope upeon the order of the Governer of Albay. Government vehicles from the Phillipine Army were dispatched to load evacuees from designated pickup points located in village centers.

Hazard Zone Mapping

Hazard Zone Mapping allows the areas of greatest danger and highest risk around a volcano to be defined. The danger zones are pointed out so the people who are living in those areas or danger zones can be evacuated. Pyroclastic flows observed in 1984, 2000 and 2001 were clocked at about 55m/s as they rushed down the middle slops, but the pyroclastic clows do not go well beyond 6km from the summit. This observation is hence incorperated in the hazard map for Mayon. For additional safety, an 'Extended Danger Zone' was recommended in the southeast, considering that the reach of the pyroclastic flows may exceed 6km. Diligent monitoring and cooperation between authorities and scientists have resulted in zero casualties for the eruptions in the years 2000 and 2001.

Appropriate Response
1. Philippine Institute of Volcanology and Seismology (PHIVOLCS) observed the number of recorded volcanic earthquakes and adjusted Alert Level according to the frequency of the quakes in order to warn the citizens

2. 15 December 2009, Albay Province authorities moved about 20000 residents out of the 8km danger zone and into local evacuation centres early in the morning. By 17 December, a total of 33833 people were evacuated.

3. Philippine Military cordoned off civilian from entering into the 8km danger zone.